Assalamu alaikum,
Do you know any wesite where I can download islamic books for free?

Assalaam alaikum,

http://www.geocities.com/kkhaan/books.html
Try this link.

Salafi Publications (http://salafiviews.com/publications.html)

Wa alaikum salaam

Assalamu alaikum
I read a lot from this site. It's quite good.
Harun Yahya - An Invitation to The Truth (http://www.harunyahya.com/en.m_book_index.php)